U.S. patent application number 17/526501 was filed with the patent office on 2022-07-21 for color conversion panel and display device including the same.
This patent application is currently assigned to Samsung Display Co., LTD.. The applicant listed for this patent is Samsung Display Co., LTD.. Invention is credited to Kang Soo HAN, Jeong Ki KIM, Jong-Hoon KIM, Hwa Yeul OH, Hye Jun WOO.
Application Number | 20220231200 17/526501 |
Document ID | / |
Family ID | 1000006012221 |
Filed Date | 2022-07-21 |
United States Patent
Application |
20220231200 |
Kind Code |
A1 |
KIM; Jeong Ki ; et
al. |
July 21, 2022 |
COLOR CONVERSION PANEL AND DISPLAY DEVICE INCLUDING THE SAME
Abstract
A color conversion panel includes light blocking members spaced
apart from each other on a substrate; and a first color conversion
layer, a second color conversion layer, and a transmission layer
respectively disposed between the light blocking members, wherein
the transmission layer includes first quantum dots, and the first
quantum dots convert incident light into light having a wavelength
in a range of about 480 nm to about 530 nm.
Inventors: |
KIM; Jeong Ki; (Hwaseong-si,
KR) ; HAN; Kang Soo; (Seoul, KR) ; KIM;
Jong-Hoon; (Seoul, KR) ; OH; Hwa Yeul;
(Hwaseong-si, KR) ; WOO; Hye Jun; (Asan-si,
KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Samsung Display Co., LTD. |
Yongin-si |
|
KR |
|
|
Assignee: |
Samsung Display Co., LTD.
Yongin-si
KR
|
Family ID: |
1000006012221 |
Appl. No.: |
17/526501 |
Filed: |
November 15, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 33/502
20130101 |
International
Class: |
H01L 33/50 20060101
H01L033/50 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 19, 2021 |
KR |
10-2021-0007571 |
Claims
1. A color conversion panel comprising: light blocking members
spaced apart from each other on a substrate; and a first color
conversion layer, a second color conversion layer, and a
transmission layer respectively disposed between the light blocking
members, wherein the transmission layer includes first quantum
dots, and the first quantum dots convert incident light into light
having a wavelength in a range of about 480 nm to about 530 nm.
2. The color conversion panel of claim 1, wherein the second color
conversion layer includes second quantum dots, and the second
quantum dots convert the incident light into light having a
wavelength in a range of about 430 nm to about 680 nm.
3. The color conversion panel of claim 2, wherein the first color
conversion layer includes third quantum dots, and the third quantum
dots convert the incident light into light having a wavelength in a
range of about 600 nm to about 650 nm.
4. The color conversion panel of claim 3, wherein a content of the
first quantum dots included in the transmission layer is less than
a content of the second quantum dots included in the second color
conversion layer and a content of the third quantum dots included
in the first color conversion layer.
5. The color conversion panel of claim 3, wherein the first color
conversion layer, the second color conversion layer, and the
transmission layer further include a scattering member,
respectively, and a content of the scattering member included in
the first color conversion layer and a content of the second color
conversion layer is less than the content of the scattering member
of the transmission layer.
6. The color conversion panel of claim 5, wherein the scattering
member includes TiO.sub.2.
7. The color conversion panel of claim 3, wherein a size of the
first quantum dots is smaller than a size of the second quantum
dots, and the size of the second quantum dots is smaller than a
size of the third quantum dots.
8. The color conversion panel of claim 1, wherein a content of the
first quantum dots is in a range of about 20 wt % to about 30 wt %
of the transmission layer.
9. The color conversion panel of claim 1, wherein the transmission
layer further includes TiO.sub.2, and a content of the TiO.sub.2 is
in a range of about 5 wt % to about 6 wt % of the transmission
layer.
10. The color conversion panel of claim 1, further comprising: a
first color filter disposed between the substrate and the first
color conversion layer; a second color filter disposed between
substrate and the second color conversion layer; and a third color
filter disposed between the substrate and the transmission
layer.
11. The color conversion panel of claim 10, further comprising: a
dummy color filter overlapping the light blocking members in a
direction perpendicular to a surface of the substrate, the dummy
color filter and the third color filter being disposed on a same
layer, wherein the third color filter and the dummy color filter
are blue color filters.
12. The color conversion panel of claim 1, further comprising: a
low refraction layer disposed between the first, second, and third
color filters, and the first and second color conversion layers and
the transmission layer.
13. The color conversion panel of claim 12, further comprising: a
low refraction capping layer contacting the low refraction
layer.
14. A display device comprising: a color conversion panel; and a
display panel overlapping the color conversion panel, wherein the
display panel emits a blue light, and the color conversion panel
includes: light blocking members spaced apart from each other on a
substrate; and a first color conversion layer, a second color
conversion layer, and a transmission layer respectively disposed
between the light blocking members, the transmission layer includes
first quantum dots, and the first quantum dots convert the blue
light from the display panel into light having a wavelength in a
range of about 480 nm to about 530 nm.
15. The display device of claim 14, wherein the second color
conversion layer includes second quantum dots, the second quantum
dots convert the incident blue light into a light having a
wavelength in a range of about 480 nm to about 560 nm, the first
color conversion layer includes third quantum dots, and the third
quantum dots convert the incident blue light into light having a
wavelength in a range of about 600 nm to about 650 nm.
16. The display device of claim 15, wherein a content of the first
quantum dots included in the transmission layer is less than a
content of the second quantum dots included in the second color
conversion layer and a content of the third quantum dots included
in the first color conversion layer.
17. The display device of claim 15, wherein the first color
conversion layer, the second color conversion layer, and the
transmission layer further include a scattering member,
respectively, and a content of the scattering member included in
the first color conversion layer and a content of the second color
conversion layer is less than a content of the scattering member of
the transmission layer.
18. The display device of claim 15, wherein a size of the first
quantum dots is smaller than a size of the second quantum dots, and
the size of the second quantum dots is smaller than a size of the
third quantum dots.
19. The display device of claim 14, wherein a content of the first
quantum dots is in a range of about 20 wt % to about 30 wt % of the
transmission layer.
20. The display device of claim 14, wherein the transmission layer
further includes TiO.sub.2, and a content of the TiO.sub.2 is in a
range of about 5 wt % to about 6 wt % of the transmission layer.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to and benefits of Korean
Patent Application No. 10-2021-0007571 under 35 U.S.C. .sctn. 119
filed on Jan. 19, 2021 in the Korean Intellectual Property Office,
the entire contents of which are incorporated herein by
reference.
BACKGROUND
1. Technical Field
[0002] The disclosure relates to a color conversion panel and a
display device including the same.
2. Description of the Related Art
[0003] A light emitting element is an element in which holes
supplied from an anode and electrons supplied from a cathode are
combined in an organic emission layer to form excitons, and light
is emitted while the excitons are stabilized.
[0004] The light emitting element has several merits such as a wide
viewing angle, a fast response speed, a thin thickness, and lower
power consumption such that the light emitting diode is widely
applied to various electrical and electronic devices such as a
television, a monitor, a mobile phone, etc.
[0005] Recently, a display device including a color conversion
panel has been proposed to implement a display device with high
efficiency. The color conversion panel converts incident light into
different colors. The incident light may be blue light, and the
blue light may be color-converted into red and green, respectively,
or transmitted as blue light itself. Therefore, the red color
conversion layer and the green color conversion layer may include
quantum dots for the color conversion, and the transmission layer
may not include separate quantum dots.
[0006] The above information disclosed in this background section
is only for enhancement of understanding of the background of the
disclosure, and therefore it may contain information that may not
form the prior art that may already be known to a person of
ordinary skill in the art.
SUMMARY
[0007] Embodiments provide a color conversion panel with improved
side visibility and a display device including the same.
[0008] A color conversion panel according to an embodiment may
include; light blocking members spaced apart from each other on a
substrate; and a first color conversion layer, a second color
conversion layer, and a transmission layer respectively disposed
between the light blocking members, wherein the transmission layer
may include first quantum dots, and the first quantum dots convert
incident light into light having a wavelength in a range of about
480 nm to about 530 nm.
[0009] The second color conversion layer may include second quantum
dots, and the second quantum dots may convert incident light into
light having a wavelength in a range of about 430 nm to about 680
nm.
[0010] The first color conversion layer may include third quantum
dots, and the third quantum dots may convert the incident light
into light having a wavelength in a range of about 600 nm to about
650 nm.
[0011] A content of the first quantum dots included in the
transmission layer may be less than a content of the second quantum
dots included in the second color conversion layer and a content of
the third quantum dots included in the first color conversion
layer.
[0012] The first color conversion layer, the second color
conversion layer, and the transmission layer may further include a
scattering member, respectively, and a content of the scattering
member included in the first color conversion layer and a content
of the second color conversion layer may be less than the content
of the scattering member of the transmission layer.
[0013] The scattering member may include TiO.sub.2.
[0014] A size of the first quantum dots may be smaller than a size
of the second quantum dots, and the size of the second quantum dots
may be smaller than a size of the third quantum dots.
[0015] A content of the first quantum dots may be in a range of
about 20 wt % to about 30 wt % of the transmission layer.
[0016] The transmission layer may further include TiO.sub.2, and a
content of the TiO.sub.2 may be in a range of about 5 wt % to about
6 wt % of the transmission layer.
[0017] The color conversion panel may further include a first color
filter disposed between the substrate and the first color
conversion layer; a second color filter disposed between the
substrate and the second color conversion layer; and a third color
filter disposed between the substrate and the transmission
layer.
[0018] The color conversion panel may further include a dummy color
filter overlapping the light blocking members in a direction
perpendicular to surface of the substrate, the dummy color filter
and the third color filter may be disposed on a same layer, wherein
the third color filter and the dummy color filter may be blue color
filters.
[0019] The color conversion panel may further include a low
refraction layer disposed between the first, second, and third
color filters, and the first and second color conversion layers and
the transmission layer.
[0020] The color conversion panel may further include a low
refraction capping layer contacting the low refraction layer.
[0021] A display device according to an embodiment may include a
color conversion panel; and a display panel overlapping the color
conversion panel, wherein the display panel emits blue light, and
the color conversion panel may include light blocking members
spaced apart from each other on a substrate; a first color
conversion layer, a second color conversion layer, and a
transmission layer respectively disposed between the light blocking
members, and the transmission layer may include first quantum dots,
and the first quantum dots convert the blue light from the display
panel into light having a wavelength in a range of about 480 nm to
about 530 nm.
[0022] The second color conversion layer may include second quantum
dots, the second quantum dots may convert the incident blue light
into light having a wavelength in a range of about 480 nm to about
560 nm, the first color conversion layer may include third quantum
dots, and the third quantum dots convert the incident blue light
into light having a wavelength in a range of about 600 nm to about
650 nm.
[0023] A content of the first quantum dots included in the
transmission layer may be less than a content of the second quantum
dots included in the second color conversion layer and a content of
the third quantum dots included in the first color conversion
layer.
[0024] The first color conversion layer, the second color
conversion layer, and the transmission layer may further include a
scattering member, respectively, and a content of the scattering
member included in the first color conversion layer and a content
of the second color conversion layer may be less than a content of
the scattering member of the transmission layer.
[0025] A size of the first quantum dots may be smaller than a size
of the second quantum dots, and the size of the second quantum dots
may be smaller than a size of the third quantum dots.
[0026] A content of the first quantum dots may be in a range of
about 20 wt % to about 30 wt % of the transmission layer.
[0027] The transmission layer may further include TiO.sub.2, and a
content of the TiO.sub.2 may be in a range of about 5 wt % to about
6 wt % of the transmission layer.
[0028] According to an embodiment, the color conversion panel with
improved side visibility and the display device including the same
are provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The above and other aspects and features of the disclosure
will become more apparent by describing in detail embodiments
thereof with reference to the attached drawings, in which:
[0030] FIG. 1 is a schematic cross-sectional view schematically
showing a color conversion panel according to an embodiment.
[0031] FIG. 2 is a view showing a configuration in which light is
emitted in all directions by quantum dots in a color conversion
layer including quantum dots QD.
[0032] FIG. 3 is a view showing a path of light in a transmission
layer including TiO.sub.2.
[0033] FIG. 4 is a view showing a spectrum of blue light.
[0034] FIG. 5 is a view showing a spectrum of green light.
[0035] FIG. 6 is a view overlapping a spectrum of blue light of
FIG. 4 and a spectrum of green light of FIG. 5.
[0036] FIG. 7 is a view showing a transmission layer including a
scattering member and third quantum dots according to an
embodiment.
[0037] FIG. 8 is a view schematically showing a display device
according to an embodiment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0038] The disclosure will be described more fully hereinafter with
reference to the accompanying drawings, in which embodiments are
shown. As those skilled in the art would realize, the described
embodiments may be modified in various different ways, all without
departing from the spirit or scope of the disclosure.
[0039] The drawings and description are to be regarded as
illustrative in nature and not restrictive. Like reference numerals
designate like elements throughout the specification.
[0040] Further, since sizes and thicknesses of constituent members
shown in the accompanying drawings are arbitrarily given for better
understanding and ease of description, the disclosure is not
limited to the illustrated sizes and thicknesses. In the drawings,
the thicknesses of layers, films, panels, regions, etc., are
exaggerated for clarity. In the drawings, for better understanding
and ease of description, the thicknesses of some layers and areas
are exaggerated.
[0041] As used herein, the singular forms, "a," "an," and "the" are
intended to include the plural forms as well, unless the context
clearly indicates otherwise.
[0042] In the specification and the claims, the term "and/or" is
intended to include any combination of the terms "and" and "or" for
the purpose of its meaning and interpretation. For example, "A
and/or B" may be understood to mean "A, B, or A and B." The terms
"and" and "or" may be used in the conjunctive or disjunctive sense
and may be understood to be equivalent to "and/or."
[0043] In the specification and the claims, the phrase "at least
one of" is intended to include the meaning of "at least one
selected from the group of" for the purpose of its meaning and
interpretation. For example, "at least one of A and B" may be
understood to mean "A, B, or A and B."
[0044] It will be understood that, although the terms first,
second, etc., may be used herein to describe various elements,
these elements should not be limited by these terms. These terms
are only used to distinguish one element from another element. For
example, a first element may be referred to as a second element,
and similarly, a second element may be referred to as a first
element without departing from the scope of the disclosure.
[0045] It will be understood that when an element such as a layer,
film, region, or substrate is referred to as being "on" another
element, it can be directly on the other element or intervening
elements may also be present. In contrast, when an element is
referred to as being "directly on" another element, there are no
intervening elements present. Further, in the specification, the
word "on" or "above" means positioned on or below the object
portion, and does not necessarily mean positioned on the upper side
of the object portion based on a gravitational direction.
[0046] For example, the spatially relative terms "below",
"beneath", "lower", "above", "upper", or the like, may be used
herein for ease of description to describe the relations between
one element or component and another element or component as
illustrated in the drawings. It will be understood that the
spatially relative terms are intended to encompass different
orientations of the device in use or operation, in addition to the
orientation depicted in the drawings. For example, in the case
where a device illustrated in the drawing is turned over, the
device positioned "below" or "beneath" another device may be placed
"above" another device. Accordingly, the illustrative term "below"
may include both the lower and upper positions. The device may also
be oriented in other directions and thus the spatially relative
terms may be interpreted differently depending on the
orientations.
[0047] It will be understood that when an element (or a region, a
layer, a portion, or the like) is referred to as "being on",
"connected to" or "coupled to" another element in the
specification, it can be directly disposed on, connected or coupled
to another element mentioned above, or intervening elements may be
disposed therebetween.
[0048] It will be understood that the terms "connected to" or
"coupled to" may include a physical or electrical connection or
coupling.
[0049] The terms "overlap" or "overlapped" mean that a first object
may be above or below or to a side of a second object, and vice
versa. Additionally, the term "overlap" may include layer, stack,
face or facing, extending over, covering, or partly covering or any
other suitable term as would be appreciated and understood by those
of ordinary skill in the art.
[0050] When an element is described as `not overlapping` or `to not
overlap` another element, this may include that the elements are
spaced apart from each other, offset from each other, or set aside
from each other or any other suitable term as would be appreciated
and understood by those of ordinary skill in the art.
[0051] The terms "face" and "facing" mean that a first element may
directly or indirectly oppose a second element. In a case in which
a third element intervenes between the first and second element,
the first and second element may be understood as being indirectly
opposed to one another, although still facing each other.
[0052] In addition, unless explicitly described to the contrary,
the word "comprises," "comprising," "includes," and/or
"including,", "has," "have," and/or "having," and variations
thereof when used in this specification, will be understood to
imply the inclusion of stated elements but not the exclusion of any
other elements.
[0053] Further, in the specification, the phrase "in a plan view"
means when an object portion is viewed from above, and the phrase
"on a cross-section" means when a cross-section taken by vertically
cutting an object portion is viewed from the side.
[0054] "About" or "approximately" as used herein is inclusive of
the stated value and means within an acceptable range of deviation
for the particular value as determined by one of ordinary skill in
the art, considering the measurement in question and the error
associated with measurement of the particular quantity (i.e., the
limitations of the measurement system). For example, "about" may
mean within one or more standard deviations, or within .+-.30%,
20%, 10%, 5% of the stated value.
[0055] Unless otherwise defined, all terms (including technical and
scientific terms) used herein have the same meaning as commonly
understood by one of ordinary skill in the art to which the
disclosure pertains. It will be further understood that terms, such
as those defined in commonly used dictionaries, should be
interpreted as having a meaning that is consistent with their
meaning in the context of the relevant art and will not be
interpreted in an idealized or overly formal sense unless expressly
so defined herein.
[0056] A color conversion panel and a display device including the
same according to an embodiment are described with reference to
accompanying drawings.
[0057] FIG. 1 is a schematic cross-sectional view schematically
showing a color conversion panel according to an embodiment.
Referring to FIG. 1, a color conversion panel 300 according to an
embodiment may include a blue color filter 230B disposed on a first
substrate 210. A dummy color filter 231B may be positioned or
disposed on a same layer as the blue color filter 230B. The dummy
color filter 231B may be disposed to be spaced apart from the blue
color filter 230B, and the dummy color filter 231B and the blue
color filter 230B may be formed through the same process and may
include the same material or similar material.
[0058] A red color filter 230R may be disposed between dummy color
filters 231B. A green color filter 230G may be disposed between the
red color filter 230R and the blue color filter 230B.
[0059] A low refraction layer 350 and a low refraction capping
layer 351 may be disposed on the color filters 230R, 230G, and 230B
and the dummy color filter 231B. The low refraction layer 350 may
include a material having a low refractive index, and the low
refraction capping layer 351 may be positioned or disposed on the
low refraction layer 350.
[0060] A light blocking member 320 may be positioned or disposed on
the low refraction capping layer 351. Light blocking members 320
may be positioned or disposed to be spaced apart from each other
via openings therebetween, and each of the openings may overlap
each color filter 230R, 230G, and 230B in a direction perpendicular
or substantially perpendicular to the surface of the first
substrate 210.
[0061] The red color conversion layer 330R, the green color
conversion layer 330G, and the transmission layer 330B are
positioned or disposed in the regions between the light blocking
member 320 spaced apart from each other. As shown in FIG. 1, a red
color conversion layer 330R, a green color conversion layer 330G,
and a transmission layer 330B may be positioned or disposed in a
space partitioned by the light blocking members 320, respectively.
A capping layer 400 may be positioned or disposed on the red color
conversion layer 330R, the green color conversion layer 330G, and
the transmission layer 330B.
[0062] The light blocking member 320 may include a black material.
The red color conversion layer 330R overlaps the red color filter
230R in a direction perpendicular to the surface of the first
substrate 210, and the green color conversion layer 330G overlaps
the red color filter 230G in the direction perpendicular to the
surface of the first substrate 210. The transmission layer 330B may
be disposed to overlap the blue color filter 230B in the direction
perpendicular to the surface of the first substrate 210.
[0063] The red color conversion layer 330R may convert the supplied
blue light to red light. For this, the red color conversion layer
330R may include first quantum dots QD1. The first quantum dots QD1
may convert the incident blue light into red light. For example, a
maximum emission peak wavelength of light emitted by the first
quantum dots QD1 may be about 600 nm or more, for example, about
610 nm or more, about 615 nm or more, or about 620 nm or more, and
about 650 nm or less, about 645 nm or less, about 640 nm or less,
about 635 nm or less, or about 630 nm or less.
[0064] The diameter of the first quantum dots QD1 may be in a range
of about 5 nm to about 6 nm. However, this is only an example and
it is not limited thereto. Among the red color conversion layer
330R, the content of the first quantum dots QD1 may be in a range
of about 30 wt % to about 50 wt %. The red color conversion layer
330R may include TiO.sub.2. Among the red color conversion layer
330R, the content of TiO.sub.2 may be in a range of about 4 wt % to
about 5 wt %.
[0065] The green color conversion layer 330G may convert the
supplied blue light to green light. The green color conversion
layer 330G may include a second quantum dots QD2. The second
quantum dots QD2 may convert the incident blue light into green
light. For example, the second quantum dots QD2 may convert the
incident light into light having a wavelength in a range of about
430 nm to about 680 nm. At this time, the maximum emission peak
wavelength of light emitted by the second quantum dots QD2 may be
about 480 nm or more, for example, about 500 nm or more, about 510
nm or more, about 520 nm or more, or about 530 nm or more, and
about 560 nm or less, about 550 nm or less, about 545 nm or less,
about 540 nm or less, or about 535 nm or less.
[0066] The diameter of the second quantum dots QD2 may be in a
range of about 3 nm to about 4 nm. However, this is only an example
and it is not limited thereto. Among the green color conversion
layer 330G, the content of the second quantum dots QD2 may be in a
range of about 30 wt % to about 50 wt %. The green color conversion
layer 330G may include TiO.sub.2. Among the green color conversion
layer 330G, the content of TiO.sub.2 may be in a range of about 4
wt % to about 5 wt %.
[0067] The transmission layer 330B transmits the incident blue
light. The transmission layer may include a transparent polymer,
and the supplied blue light is transmitted and represents blue. The
transmission layer 330B corresponding to the region emitting blue
light may include third quantum dots QD3.
[0068] At this time, the third quantum dots QD3 may convert the
incident blue light into a wavelength in a range of about 480 nm to
about 530 nm. At this time, the wavelength region for the color
conversion of the third quantum dots QD3 may partially overlap with
the wavelength range for the color conversion of the second quantum
dot QD2. The diameter of the third quantum dots QD3 may be in a
range of about 2 nm to about 3 nm. The content of the third quantum
dots QD3 may be in a range of about 20 wt % to about 30 wt %. It is
explained separately later, but the wavelength of the color emitted
by the third quantum dots QD3 may correspond to the wavelength of
the overlapping region of the spectrum of the blue light and the
spectrum of the green light. The transmission layer 330B may
include a scattering member, and the scattering member may be
TiO.sub.2. Among the transmission layer 330B, the content of
TiO.sub.2 may be in a range of about 5 wt % to about 6 wt %.
TiO.sub.2 included in the transmission layer 330B may improve
front/side visibility by turning the direction of the incident blue
light to the side. The third quantum dots QD3 included in the
transmission layer 330B emit the color-converted light in all
directions, thereby contributing to improving the side visibility
along with the TiO.sub.2. There may be a difference in the display
quality for each region according to the concentration gradient of
TiO.sub.2 in the transmission layer 330B, but it may be offset
while the third quantum dots QD3 included in the transmission layer
330B emit light in all directions. The effect due to the
introduction of the third quantum dots QD3 is separately described
in detail later.
[0069] For example, the content of the third quantum dots QD3 of
the transmission layer 330B may be smaller or less than the content
of the first quantum dots QD1 of the red color conversion layer
330R or the content of the second quantum dots QD2 of the green
color conversion layer 330G. The content of TiO.sub.2 of the
transmission layer 330B may be greater than the content of
TiO.sub.2 of the red color conversion layer 330R or the green color
conversion layer 330G.
[0070] In the following, the quantum dots are first described in
detail. The first quantum dot QD1, the second quantum dot QD2, and
the third quantum dot QD3 may each have features described
below.
[0071] In the specification, the quantum dots (hereinafter,
referred to as semiconductor nanocrystals) may include a Group
II-VI compound, a Group III-V compound, a Group IV-VI compound, a
Group IV element or compound, a Group compound, a Group compound, a
Group I-II-IV-VI compound, or combinations thereof.
[0072] The Group II-VI compound may be selected from a group
including a binary compound selected from a group consisting of
CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and a
mixture thereof; a ternary compound selected from a group
consisting of AgInS, CuInS, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe,
ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe,
CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and a mixture
thereof; and a quaternary compound selected from a group consisting
of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe,
HgZnSeS, HgZnSeTe, HgZnSTe, and a mixture thereof. The Group II-VI
compound may further include a Group III metal.
[0073] The Group III-V compound may be selected from a group
including a binary compound selected from a group consisting of
GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb,
and a mixture thereof; a ternary compound selected from a group
consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AINAs, AlNSb,
AlPAs, AlPSb, InGaP, InNP, InNAs, InNSb, InPAs, InZnP, InPSb, and a
mixture thereof; and a quaternary compound selected from a group
consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP,
GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb,
InAlPAs, InAlPSb, InZnP, and a mixture thereof. The Group III-V
compound may further include a Group II metal (for example,
InZnP).
[0074] The Group IV-VI compound may be selected from a group
including a binary compound selected from a group consisting of
SnS, SnSe, SnTe, PbS, PbSe, PbTe, and a mixture thereof; a ternary
compound selected from a group consisting of SnSeS, SnSeTe, SnSTe,
PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and a mixture thereof;
and a quaternary compound selected from a group consisting of
SnPbSSe, SnPbSeTe, SnPbSTe, and a mixture thereof.
[0075] The Group IV element or compound may be selected from a
group including a single element compound selected from a group
consisting of Si, Ge, and combinations thereof; and a binary
element compound selected from a group consisting of SiC, SiGe, and
combinations thereof.
[0076] The Group compound may include CuInSe.sub.2, CuInS.sub.2,
CuInGaSe, and CuInGaS, however it is not limited thereto. The Group
I-II-IV-VI compound may include CuZnSnSe and CuZnSnS, however it is
not limited thereto. The Group IV element or compound may be
selected from a group including a single element compound selected
from a group consisting of Si, Ge, and combinations thereof; and a
binary element compound selected from a group consisting of SiC,
SiGe, and combinations thereof.
[0077] The Group compound may be selected from a group consisting
of ZnGaS, ZnAlS, ZnInS, ZnGaSe, ZnAlSe, ZnlnSe, ZnGaTe, ZnAlTe,
ZnlnTe, ZnGaO, ZnAlO, ZnInO, HgGaS, HgAl S, HgInS, HgGaSe, HgAlSe,
HglnSe, HgGaTe, HgAlTe, HglnTe, MgGaS, MgAl S, MgInS, MgGaSe, MgAl
Se, MglnSe, and combinations thereof.
[0078] The Group I-II-IV-VI compound may be selected from CuZnSnSe
and CuZnSnS, however it is not limited thereto.
[0079] In an embodiment, the quantum dots may not include cadmium.
The quantum dots may include a semiconductor nanocrystal based on a
Group III-V compound including indium and phosphorus. The Group
III-V compound may further include zinc. The quantum dots may
include a semiconductor nanocrystal based on a Group II-VI compound
including a chalcogen element (for example, sulfur, selenium,
tellurium, or combinations thereof) and zinc.
[0080] In the quantum dots, the binary compound, the ternary
compound, or the quaternary compound as above-described may be
present in the particle at a uniform concentration or in the same
particle of which a concentration distribution may be partially
divided into different states. Also, they may have a core/shell
structure in which one quantum dot surrounds another quantum dot.
The interface between the core and the shell may have a
concentration gradient in which the concentration of the elements
present in the shell decreases toward the center.
[0081] In an embodiment, the quantum dots may have a core-shell
structure including a core including the above-described
nanocrystal and a shell surrounding the core. The shell of the
quantum dot may act as a protective layer for maintaining the
semiconductor characteristic by preventing a chemical modification
of the core and/or a charging layer for imparting an
electrophoretic characteristic to the quantum dot. The shell may be
single-layered or multi-layered. The interface between the core and
the shell may have a concentration gradient in which the
concentration of elements present in the shell decreases toward the
center. Examples of the shell of the quantum dot include a metal or
non-metal oxide, a semiconductor compound, or a combination
thereof.
[0082] For example, the metal or non-metal oxide may be a binary
compound such as SiO2, Al.sub.2O.sub.3, TiO.sub.2, ZnO, MnO,
Mn.sub.2O.sub.3, Mn.sub.3O.sub.4, CuO, FeO, Fe.sub.2O.sub.3,
Fe.sub.3O.sub.4, CoO, Co.sub.3O.sub.4, and NiO, or a ternary
compound such as MgAl.sub.2O.sub.4, CoFe.sub.2O.sub.4,
NiFe.sub.2O.sub.4, and CoMn.sub.2O.sub.4, however the disclosure is
not limited thereto.
[0083] Also, the semiconductor compound may be CdS, CdSe, CdTe,
ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe,
InAs, InP, InGaP, InSb, AlAs, AlP, and AlSb, however the disclosure
is not limited thereto.
[0084] An interface between the core and the shell may have a
concentration gradient, such that the concentration of an element
existing in the shell is gradually reduced as it nears the center
thereof. The semiconductor nanocrystals may have a structure
including one semiconductor nanocrystal core and multi-layered
shells surrounding the core. In an embodiment, the multi-layered
shells may have two or more layers, for example, two, three, four,
five, or more layers. Two adjacent layers of the shell may have a
single composition or different compositions. In the multi-layered
shell, each layer may have a composition that varies along the
radius.
[0085] The quantum dots may have a full width at half maximum
(FWHM) of about 45 nm or less, about 40 nm or less, or about 30 nm
or less, and may improve color purity or color reproducibility in
this range. Also, since light emitted through the quantum dots is
emitted in all directions, a wide viewing angle may be
improved.
[0086] In the quantum dots, the shell material and the core
material may have different energy bandgaps from each other. For
example, the energy bandgap of the shell material may be greater
than that of the core material. As an example, the energy bandgap
of the shell material may be smaller than that of the core
material. The quantum dots may have a multi-layered shell. In the
multi-layered shell, the energy bandgap of the outer layer may be
greater than the energy bandgap of the inner layer (for example,
the layer nearer to the core). In the multi-layered shell, the
energy bandgap of the outer layer may be less than the energy
bandgap of the inner layer.
[0087] The quantum dots may control an absorption/emission
wavelength by adjusting a composition and a size thereof. A maximum
peak emission wavelength of the quantum dot may be an ultraviolet
(UV) to infrared wavelength, or a wavelength of greater than the
above wavelength range.
[0088] The quantum dot may have quantum efficiency of about 10% or
more, for example, about 30% or more, about 50% or more, about 60%
or more, about 70% or more, about 90% or more, or even 100%. The
quantum dots can have a relatively narrow spectrum. The quantum
dots may have a full width at half maximum of a light emission
wavelength spectrum of, for example, about 50 nm or less, about 45
nm or less, about 40 nm or less, or about 30 nm or less.
[0089] The quantum dots may have a particle size of about 1 nm or
more and about 100 nm or less. The size of the particle refers to
the diameter of the particle or the diameter converted by assuming
a sphere from a 2D image obtained by an analysis with a
transmission electron microscope. The quantum dots may have the
size in a range of about 1 nm to about 20 nm, for example, about 2
nm or more, about 3 nm or more, or about 4 nm or more, and about 50
nm or less, and about 40 nm or less, about 30 nm or less, about 20
nm or less, about 15 nm or less, or about 10 nm or less. The shape
of the quantum dots is not specially limited. For example, the
shape of the quantum dots may include substantially a sphere,
substantially a polyhedron, substantially a pyramid, substantially
a multi-pod, substantially a square, substantially a cuboid,
substantially a nanotube, substantially a nanorod, substantially a
nanowire, substantially a nanosheet, or a combination thereof, but
is not limited thereto.
[0090] The quantum dots may be commercially available or may be
synthesized appropriately. For the quantum dots, the particle size
may be controlled relatively freely during a colloid synthesis and
the particle size may also be uniformly controlled.
[0091] The quantum dots may include an organic ligand (for example,
having a hydrophobic moiety). The organic ligand moiety may be
bound to surfaces of the quantum dots. The organic ligand moiety
may include RCOOH, RNH.sub.2, R.sub.2NH, R.sub.3N, RSH, R.sub.3PO,
R.sub.3P, ROH, RCOOR, RPO (OH).sub.2, RHPOOH, R.sub.2POOH, or
combinations thereof, and herein, R is independently a C3 to C40
substituted or unsubstituted aliphatic hydrocarbon group such as a
C3 to C40 (for example, C5 or greater and C24 or smaller)
substituted or unsubstituted alkyl, or a substituted or
unsubstituted alkenyl, a C6 to C40 (for example, C6 or greater and
C20 or smaller) substituted or unsubstituted aromatic hydrocarbon
group such as a substituted or unsubstituted C6 to C40 aryl group,
or a combination thereof.
[0092] Examples of the organic ligand may be a thiol compound such
as methane thiol, ethane thiol, propane thiol, butane thiol,
pentane thiol, hexane thiol, octane thiol, dodecane thiol,
hexadecane thiol, octadecane thiol, or benzyl thiol; an amine such
as methane amine, ethane amine, propane amine, butane amine, pentyl
amine, hexyl amine, octyl amine, nonylamine, decylamine, dodecyl
amine, hexadecyl amine, octadecyl amine, dimethyl amine, diethyl
amine, dipropyl amine, tributylamine, or trioctylamine; a
carboxylic acid compound such as methanoic acid, ethanoic acid,
propanoic acid, butanoic acid, pentanoic acid, hexanoic acid,
heptanoic acid, octanoic acid, dodecanoic acid, hexadecanoic acid,
octadecanoic acid, oleic acid, or benzoic acid; a phosphine
compound such as methyl phosphine, ethyl phosphine, propyl
phosphine, butyl phosphine, pentyl phosphine, octylphosphine,
dioctyl phosphine, tributylphosphine, or trioctylphosphine; a
phosphine compound or an oxide compound thereof such as methyl
phosphine oxide, ethyl phosphine oxide, propyl phosphine oxide,
butyl phosphine oxide pentyl phosphine oxide, tributylphosphine
oxide, octylphosphine oxide, dioctyl phosphine oxide, or
trioctylphosphine oxide; a diphenyl phosphine, a triphenyl
phosphine compound, or an oxide compound thereof; a C5 to C20 alkyl
phosphonic acid such as hexylphosphinic acid, octylphosphinic acid,
dodecanephosphinic acid, tetradecanephosphinic acid,
hexadecanephosphinic acid, or octadecanephosphinic acid; and the
like, but are not limited thereto. The quantum dots may include a
hydrophobic organic ligand alone or in a mixture of at least two
types thereof. The hydrophobic organic ligand may not include a
photopolymerizable moiety (for example, an acrylate group, a
methacrylate group, etc.).
[0093] The effect of the color conversion panel in which the third
quantum dots QD3 is included in the transmission layer 330B
according to an embodiment is described.
[0094] The red color conversion layer 330R and the green color
conversion layer 330G in the color conversion panel convert the
incident blue light into red light by including the quantum dots.
The transmission layer 330B transmits blue light and does not
color-convert separately. At this time, since the quantum dots for
the color conversion are not included in the transmission layer
330B, a scattering member may be included instead of the quantum
dots. The scattering member used at this time may be TiO.sub.2.
[0095] Since the quantum dots emit light in all directions, they
may reduce the difference between the front visibility and the side
visibility. FIG. 2 shows the configuration in which light is
emitted in all directions by the quantum dots in the color
conversion layer 330 including the quantum dots QD. As shown in
FIG. 2, the quantum dots QD emit light in all directions, so they
may produce the same display quality no matter whether it is being
viewed from the front or the side. In FIGS. 2 and 3, a color filter
230 may include 230R, 230G, and/or 230B.
[0096] However, in the case of the transmission layer 330B that may
not include the quantum dots, light is transmitted in only one
direction or a direction due to the straightness of the light.
Therefore, there is a problem that there is a difference in the
front visibility and the side visibility, the light is dispersed by
including the scattering member in the transmission layer 330B. In
the case of the scattering member such as TiO.sub.2, the difference
in the front/side luminance may be reduced by converting the light
traveling in the front direction to the side.
[0097] FIG. 3 is a view showing a path of light in a transmission
layer in TiO.sub.2. As shown in FIG. 3, the light incident on the
straight line is diverted through TiO.sub.2 and emitted to the
side. Therefore, a WAD characteristic may be improved by reducing
the difference in the front/side luminance.
[0098] However, in the case of the transmission layer 330B that
does not include the quantum dots and may include only TiO.sub.2,
since the dependence of TiO.sub.2 is large, the occurrence rate of
defects due to the content deviation of TiO.sub.2 for each position
may be high. In the transmission layer 330B, a difference in the
display quality occurs between a region with the high content
TiO.sub.2 and a region with the low content TiO.sub.2, which may be
recognized as bright line/dark lines or divided into strong/weak
visibility regions on the panel.
[0099] However, in the display device according to an embodiment,
the transmission layer 330B may include the third quantum dots QD3.
The third quantum dots QD3 may emit light having the wavelength of
the spectrum overlapping region of light emitted from the
transmission layer 330B and light emitted from the green color
conversion layer 330G, and the light incident into the transmission
layer 330B is dispersed in the several directions by the third
quantum dots QD3, thereby improving the front/side visibility.
[0100] The wavelength of light that is color-converted by the third
quantum dots QD3 is described in detail.
[0101] FIG. 4 shows the spectrum of blue light. Referring to FIG.
4, it may be observed that the blue light has a wavelength in a
range of about 430 nm to about 530 nm and a peak is formed at about
470 nm.
[0102] FIG. 5 shows the spectrum of green light. Referring to FIG.
5, it may be observed that the green light has a wavelength of
approximately 430 nm to 680 nm, and a low peak appears near about
470 nm and the high peak appears near about 560 nm.
[0103] FIG. 6 shows overlapping of the spectrum of the blue light
of FIG. 4 and the spectrum of the green light of FIG. 5. Referring
to FIG. 6, in the wavelength region in a range of about 480 nm to
about 530 nm, it may be observed that the spectrum of the blue
light and the spectrum of the green light are overlapped.
[0104] In the color conversion panel according to an embodiment,
the transmission layer 330B may include the third quantum dots QD3
and the third quantum dots QD3 that color-convert the incident blue
light into the light of the wavelength in a range of about 480 nm
to about 530 nm. As observed in FIG. 4, the corresponding
wavelength region is a region included in the spectrum of the blue
light, and the color conversion by the third quantum dots QD3 does
not affect the display quality of the blue light.
[0105] As shown in FIG. 2, the quantum dots QD reduce the
difference in the front/side luminance while emitting the incident
light in all directions, thereby improving the display quality.
[0106] FIG. 7 shows the transmission layer 330B including the
scattering member TiO.sub.2 and the third quantum dots QD3
according to an embodiment. As shown in FIG. 7, the scattering
member TiO.sub.2 changes the direction of the front light through
TiO.sub.2 to be emitted to the side, thereby increasing the light
path at the inside. The third quantum dots QD3 compensate for the
deviation due to the difference in the concentration TiO.sub.2 for
each region while emitting the light in all directions. For
example, the display quality may be different as the concentration
of TiO.sub.2 is different for each region within the transmission
layer 330B, but the deviation of the concentration TiO.sub.2 may be
offset through a Lambertian emission characteristic of the third
quantum dots QD3 and a WAD characteristic may be improved.
[0107] Also, as above-described, as the third quantum dots QD3 are
included in the transmission layer 330B, the thickness of the
transmission layer 330B may be thinly formed.
[0108] Since the transmission layer 330B transmits the incident
blue light, the efficiency increases in case that the thickness of
the transmission layer 330B decreases. However, in case that the
thickness of the transmission layer 330B decreases in this way,
since the optical path inside the transmission layer 330B is
shortened, the content of TiO.sub.2 must be increased to match the
front/side visibility. In case that the content of TiO.sub.2
increases in this way, there is a high possibility that the
difference in the concentration of TiO.sub.2 for each region may
occur in the transmission layer 330B, and this may lead to the
deterioration of the display quality.
[0109] However, in an embodiment, the transmission layer 330B may
include the third quantum dots QD3. Accordingly, the luminance
difference of the front/side may decrease through the Lambertian
emission characteristic of the third quantum dots QD3, and
accordingly, the transmission layer 330B may be formed with the
thin thickness and efficiency may increase.
[0110] Also, since the transmission layer 330B may include the
quantum dots like the red color conversion layer 330R or the green
color conversion layer 330G, the characteristic change due to the
thickness change is similar. Therefore, it is easy to derive the
optimum thickness at which the efficiency of the transmission layer
330B, the red color conversion layer 330R, and the green color
conversion layer 330G is maximized. In case that the transmission
layer 330B does not include the quantum dots, it is not easy to
derive a common optimal thickness because the efficiency according
to the thickness occurs differently from the red color conversion
layer 330R and the green color conversion layer 330G including the
quantum dots. However, in an embodiment, since the transmission
layer 330B, the red color conversion layer 330R, and the green
color conversion layer 330G all include the quantum dots, it is
possible to easily derive the optimum thickness.
[0111] The display device including the color conversion panel 300
according to an embodiment is described with reference to FIG. 8.
FIG. 8 is a view schematically showing a display device according
to an embodiment.
[0112] FIG. 8 may include a display panel 100 and the color
conversion panel 300. The display panel 100 may include a second
substrate 110, transistors TFT, and an insulating layer 180
disposed on the second substrate 110. A first electrode 191 and a
partition wall or bank 360 may be disposed on the insulating layer
180, and the first electrode 191 may be disposed in the opening of
the partition wall or bank 360 and may be electrically connected to
the transistor TFT. The transistor TFT may include a semiconductor
layer, a source electrode, and a drain electrode electrically
connected to the semiconductor layer, and a gate electrode
insulated from the semiconductor layer. A second electrode 270 may
be positioned or disposed on the partition wall or bank 360, and a
light-emitting element layer 370 may be positioned or disposed
between the first electrode 191 and the second electrode 270. The
first electrode 191, the second electrode 270, and a light-emitting
element layer 370 may be collectively referred to as a
light-emitting element ED.
[0113] The description for the color conversion panel 300 is the
same as that of FIG. 1. The detailed description of the same
constituent elements is omitted. For example, the blue color filter
230B, the dummy color filter 231B, the red color filter 230G, and
the green color filter 230R may be positioned or disposed on the
second substrate 210.
[0114] The low refraction layer 350 and the low refraction capping
layer 351 may be disposed on the color filters 2308, 230G, and 230B
and the dummy color filter 231B. The red color conversion layer
330R, the green color conversion layer 330G, and the transmission
layer 330B may be positioned or disposed on the low refraction
capping layer 351. The light blocking member 320 is disposed
between the red color conversion layer 330R, the green color
conversion layer 330G, and the transmission layer 330B.
[0115] The light blocking member 320 of the color conversion panel
300 may overlap the partition wall or bank 360 of the display panel
100 in the direction perpendicular to the surface of the first
substrate 210. Also, each of the red color conversion layer 330R,
the green color conversion layer 330G, and the transmission layer
330B may overlap the light-emitting element ED in the direction
perpendicular to the surface of the first substrate 210.
[0116] As above-described, the transmission layer 330B may include
the scattering member TiO.sub.2 and the third quantum dots QD3, and
the third quantum dots GD3 color-convert the incident light into
the light having the wavelength in a range of about 480 nm to about
530 nm. Therefore, by dispersing the light incident on the
transmission layer 330B into the front and the side, the difference
in the luminance of the front/side may be improved, and the
difference in the display quality due to the difference in the
content TiO.sub.2 for each region may be offset.
[0117] While this disclosure has been described in connection with
what is considered to be practical embodiments, it is to be
understood that the disclosure is not limited to the disclosed
embodiments. On the contrary, it is intended to cover various
modifications and equivalent arrangements included within the
spirit and scope of the disclosure and the appended claims.
* * * * *